1. Field of the Invention
The present invention is directed generally to an image forming apparatus, an image forming method in an image forming apparatus, and a computer program product.
2. Description of the Related Art
Image forming apparatuses that have, as one of operating modes, a power save mode (hereinafter, “sleep mode”) to reduce electric power consumption when the apparatus is idle have been conventionally provided. An image forming apparatus having a power save mode typically reduces electric power consumption when idle (hereinafter, “sleep-mode power consumption”) by causing the apparatus to stop operating after a predetermined period of receiving no operating input. However, even while the image forming apparatus is in the power save mode, the apparatus is still consuming a small amount of electric power. In view of the circumstances, for further reduction of sleep-mode power consumption and improvement in safety, a technique of turning off a power switch of an apparatus to thereby cut off the apparatus from power supply has been employed.
However, cutting off an image forming apparatus that includes, for instance, a hard disk drive, from power supply in response to switch-off of a power switch can result in occurrence of an inconvenient condition to be described below. Specifically, when the apparatus is cut off from the power supply while the apparatus is making access to the hard disk drive, data loss, data damage, improper writing of essential data to the hard disk drive, or the like inconvenient condition can occur. To this end, image forming apparatuses having shutdown function have been provided in recent years (see, e.g., Japanese Patent Application Laid-open No. 2004-276588). When a power switch of such an image forming apparatus having the shutdown function is switched off, power supply to the apparatus is cut off upon completion of operation that has been during processing at the instant of switch-off of the power switch rather than immediately after the switch-off of the power switch.
As described above, an image forming apparatus having the shutdown function is typically configured such that power supply to the apparatus is cut off upon completion of operation that has been during processing at the instant of switch-off of power switch. Accordingly, in the image forming apparatus having the shutdown function, electric power is continuously supplied not only to a device involved in operation that has been during processing at the instant of switch-off of the power switch but also to other devices that are not involved in the operation until completion of the operation, resulting in waste of electric power disadvantageously.